Login/password

Login and password

Secure Shell Login and File Transfer

To be able to access HPC2N clusters from a remote computer using your login name and password, you need to use a secure shell (optionally with GSSAPI for passwordless login). On GNU/Linux, OS X, and other Unix-like operating systems we recommend using OpenSSH's ssh (secure shell) for login and scp (secure copy) for file transfer. The following table shows recommended clients for all major platforms:

Documentation can be found on the above sites or by typing man ssh or man scp if you're using a terminal emulator. You can also get more information on our SSH X11 forwarding page. The following example shows connecting to Abisko from your local machine and copying a file (found in your home directory) from Abisko to the /tmp directory on your local machine:

Passwordless login

NOTE: SSH Key-Based Authentication does NOT work on any of HPC2N's systems.

However, you can use Kerberos/GSSAPI based authentication to access HPC2N's systems instead. GSSAPI allows you to type your password once when obtaining your Kerberos ticket, and while that ticket is valid you don't have to retype your password.

GSSAPI with ssh and PuTTY clients

For the ssh client, enable the following configuration options in $HOME/.ssh/config:

Note that the Host keyword restricts the subsequent declarations to a specific host or domain (HPC2N). Also note that for the above options to work, the ssh client had to be previously compiled with the configuration option --with-kerberos5. Most major GNU/Linux distributions offer their standard ssh client with this option turned on.

Before running the ssh command make sure you have a valid Kerberos ticket (klist command) or obtain one by running the kinit command.

$ kinit <username>@HPC2N.UMU.SE

On Windows users can use PuTTY. In PuTTY configuration menu Connection –> Auth make sure that both of the Kerberos 5 GSSAPI boxes are checked, to attempt GSSAPI authentication and to allow GSSAPI credential delegation.

First Time Login / Password Change

The first time you log in to any HPC2N system (see the section above on how to log in using ssh) you must change your password. This is done using the passwd command:

t-mn01 [~]$ passwd

Use a good password that combines letters of different case. Do not use dictionary words. Avoid using the same password that you also use in other places.

It will first ask for your current password. Type in that and press enter. Then type in the new password, enter, and repeat. You have changed the password.

Forgotten Password

If you forget your password it can be restored using the Password restore service. It requires that you have a SUPR id and that your account at HPC2N is connected to your SUPR id.